Based on studies, the University of California, Los Angeles, put forward the theory that a large amount of muscle mass in an elderly person significantly reduces the risk of premature death . Research data confirm the evidence of the importance of overall body composition. It is the structural features of the body, and not the commonly used body mass index, that are the most effective way to prevent early death.
The results of the study were published in the American Journal of Medicine and were the culmination of an experiment conducted a little earlier. The experiment was led by Dr. Preethi Srikanthan, a clinical associate professor at the endocrinology department of David Geffen School of Medicine, located at the University of California, Los Angeles. The experiment proved that the structure of muscle mass significantly reduces the risk of metabolic syndrome formation.
“There is no gold standard in body composition measurements. More than one study was conducted on this issue and each had its own measurement technique, and as a result of each, different results were obtained, ”Srikantan says. - In addition, a considerable number of studies on the effect of obesity on mortality rates use body mass index (BMI) as the main indicator. However, our experiment shows that doctors who advise older people on measures to prevent serious illness and early death need to concentrate not only on BMI, but also on improving body composition. ”
From 1988 to 1994, the third National Health and Nutrition Examination Survey (NHANES) was conducted. Of the total number of subjects, a group consisting of 3659 women and men was allocated. The age category of men at the time of the study was 55 years and older, and the female age category was 65 years and older. A second study was conducted in 2004. After analyzing the data of both studies, scientists found how many respondents died due to natural causes.
Using bioimpedanceometry (BIA), which is the transmission of current through the body, the body composition of all subjects was evaluated. The essence of bioimpedansometry is that current flows more freely through the muscles than through fat, since muscle tissue contains much more water. This method allowed scientists to determine the ratio of muscle volume and human growth (muscle mass index), similar to body mass index. The aim of the study was to determine the relationship between muscle mass index and the possibility of death.
As a result, it was found that the examined people with the most significant level of muscle mass had the lowest risk of death from any natural causes in comparison with those whose muscle volume was minimal.
According to one of the study's initiators, Dr. Arun Karlamangla, an associate professor at the Geriatrics Department of the School of Medicine, David Geffen: “According to the findings, the more muscle you have, the lower the risk of premature death. As a result, instead of worrying about weight or body mass index, people should maximize and maintain muscle mass. ”
Of course, this work has some limitations. For example, it is not possible to establish a causal relationship between survival and muscle mass on the basis of even such an extensive study as NHANES III.
According to Srikantan, it is precisely the level of muscle mass that is the most important prognostic risk factor for premature death. In addition, it is important that bioimpedanceometry is not the only possible measurement technique and is not the most modern, although all measurements during NHANES III were carried out as carefully as possible and most corresponded to the level of research.
Based on the studies, Srikantan and Karlamangla made a definite conclusion: “Despite some limitations, the scientific work carried out and the data of the national large study established in its process made it possible to establish the level of muscle mass measured using bioimpedansometry in elderly people is a prognostic independent factor. At the same time, the statement about the relationship between the body mass index and the mortality rate of older people proved complete failure. Therefore, it is extremely important to add a measurement of muscle mass in relation to growth in the general examination of the elderly when undergoing a medical examination. In addition, additional research is of great importance in order to determine the necessary type and duration of training, affecting the increase in muscle mass and, accordingly, on the life expectancy of elderly people. ”